Genetic impacts of shrimp trawling on red snapper (Lutjanus campechanus) in the northern Gulf of Mexico     

Saillant  Eric; Bradfield  S. Coleen; Gold  John R. 《ICES Journal of Marine Science》2006,63(4):705-713

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Trends in the solubility of iron,aluminium, manganese and phosphorus in aerosol collected over the Atlantic Ocean     

A.R. Baker  T.D. Jickells  M. Witt  K.L. Linge 《Marine Chemistry》2006

The solubility of iron, aluminium, manganese and phosphorus has been determined in aerosol samples collected between 49°N and 52°S during three cruises conducted in the Atlantic Ocean as part of the European Union funded IRONAGES programme. Solubilities (defined at pH 4.7) determined for Fe and Al in samples of Saharan dust were significantly lower (medians 1.7% and 3.0%, respectively) than the solubilities of these metals in aerosols from other source regions (whole dataset medians 5.2% and 9.0%, respectively). Mn solubility also varied with aerosol source, but the median solubility of Mn in Saharan dust was very similar to the median for the dataset as a whole (55% and 56%, respectively). The observed solubility of aerosol P was ∼ 32%, with P solubility in Saharan aerosol perhaps as low as 10%. Laboratory studies have indicated that aerosol Fe solubility is enhanced by acid processing. No relationship could be found between Fe solubility and the concentrations of acid species (non-seasalt SO₄²⁻, NO₃⁻) nor the net acidity of the aerosol, so we are unable to confirm that this process is significant in the atmosphere. In terms of the supply of soluble Fe to oceanic ecosystems on a global scale, the observed higher solubility for Fe in non-Saharan aerosols is probably not significant because the Sahara is easily the dominant source of Fe to the Atlantic. On a smaller scale however, higher solubility for aerosol Fe may alter our understanding of Fe cycling in regions such as the remote Southern Ocean.  相似文献   

Microzooplankton production in the oceans   总被引：7，自引：0，他引：7  

Landry  Michael R.; Calbet  Albert 《ICES Journal of Marine Science》2004,61(4):501-507

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Geochemical cycling in the Hooghly estuary, India     

B. L. K. Somayajulu  R. Rengarajan  R. A. Jani 《Marine Chemistry》2002,79(3-4)

U–Th decay series isotopes, δ¹⁸O and Si measurements in the river estuarine waters and sediments of the polluted Hooghly estuary as well as the surface waters of the Bay of Bengal, its high salinity end member, are reported. Dissolved Si indicates that there are probably two mixing regimes, dissolved U behaviour is nonconservative and δ¹⁸O behaves conservatively in the overall estuarine region. Isotopes of reactive elements, viz. ²³⁴Th and ²¹⁰Po, are removed from the estuarine waters in <2 days and <1 month, respectively, which is due to high suspended matter (30–301 mg l⁻¹). ²²⁸Ra and ²²⁶Ra are profusely released into the estuarine waters in the low to mid-salinity regions.As expected, the opposite trend is observed in the case of estuarine sediments and suspended matter. Reactive isotopes of Th, ²¹⁰Pb and ²¹⁰Po are enriched, whereas Ra isotopes are depleted with respect to their parent nuclides in the estuarine sediments and suspended matter. ²³²Th/Al ratio appears well suited to study the distribution and mixing of the bed load sediments of the Ganga–Brahmaputra (G–B) and the Hooghly rivers with those from other rivers on the Bay of Bengal floor.  相似文献   

The abyssal bounty fan and lower Bounty Channel: evolution of a rifted-margin sedimentary system     

R. M. Carter  L. Carter 《Marine Geology》1996,130(3-4):181-202

The Bounty Channel and Fan system provides the basis for a model for deep-sea channel and fan development in a rifted continental margin setting. The sedimentary system results from an interplay between tectonics (fan location; sediment source), turbidity currents (sediment supply), geostrophic currents (sediment reworking and distribution) and climate (sea level, and hence sediment supply and type). Today, sediment is shed from the collisional Southern Alps, part of the Pacific/Indo-Australian plate margin, and passes east across the adjacent shelf and into the Otago Fan complex at the head of the Bounty Trough. Paths of sediment supply, and locations of sediment deposition, are controlled by the bathymetry of the Bounty Trough, with axial slopes as high as 37 m/km (2°) towards the trough head, diminishing to around 3.5 m/km (0.2°) along the trough axis. The Bounty Fan is located 800 km further east, where the Bounty Channel debouches onto abyssal oceanic crust at the mouth of the Bounty Trough. The Bounty Fan comprises a basement controlled fan-channel complex with high leveed banks exhibiting fields of mud waves, and a northward-elongated middle fan. Channel-axis gradients diminish from 6 m/km (0.35°) or more on the upper fan to less than 1 m/km (<0.06°) on the lower fan. Parts of the left bank levee and almost the entire middle fan are being eroded and re-entrained within a Deep Western Boundary Current (DWBC), which passes along the eastern New Zealand margin at depths below 2000 m. The DWBC is the prime source of deep, cold water flow into the Pacific Ocean, with a volume of ca. 20 Sv and velocities up to 4 cm/s or greater. The mouth of the Bounty Channel, at a depth of 4950 m at the south end of the middle fan, acts as a point source for an abyssal sediment drift entrained northward under the DWBC at depths below 4300 m. The Bounty Fan probably originated in the early to middle Neogene, but has mostly been built during the last 3 Myr (Plio-Pleistocene), predominantly as climate-controlled sedimentary couplets of terrigenous, micaceous mud (acoustically reflective; glacial) and biopelagic ooze (acoustically transparent; interglacial), deposited under the pervasive influence of the DWBC.  相似文献   

Optimal determination of nudging coefficients using the adjoint equations   总被引：1，自引：0，他引：1  

DAVID R. STAUFFER  JIAN-WEN BAO 《地球，A辑:动力气象学与海洋学》1993,45(5):358-369

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On the application of the units of measurement of the amount and composition of matter in oceanology     

E. I. Ovsyanyi  V. I. Zaburdaev  A. S. Romanov 《Physical Oceanography》2004,14(4):243-254

We consider the procedures of conversion of the conventional and out-of-system units of measurement of the amount and composition of matter used in oceanology to the International System of Units (SI). The coefficients of conversion are presented in the form of a table. We present the data on the units of measurement of mineralization (scales of salinity) of seawater for the oceanic range of its variability, freshened waters of internal seas, and brines. The contemporary concept of salinity as a dimensionless quantity is discussed.Translated from Morskoi Gidrofizicheskii Zhurnal, No. 4, pp. 61–72, July–August, 2004.  相似文献   

Temperature of the ocean surface as an indicator of thermodynamic processes in the northwest Pacific     

G. A. Vlasova  A. M. Polyakova 《Physical Oceanography》2004,14(5):295-302

The numerical computations and analysis of the anomalies of temperature of the ocean surface in the northwest part of the Pacific Ocean were carried out on the basis of the archival data for 1960 and 1964–1985. A five-year period of general instability of the annual average temperature was revealed (1973–1977). In this period, the year 1974 was the coldest and the year 1977 was characterized as extremely warm. We performed the analysis of the interannual and annual variability of the anomalies of temperature of the ocean surface and revealed common features and distinctions of the seasonal evolution of these anomalies for years with substantially different temperature conditions. A quasistationary zone of maximally heated waters was discovered in the band located (independently of the year and season) between 36 and 46°N to the east of 140°E. This zone coincides in space with the zone of the subarctic front and the south part of the subarctic region. The influence of the meanders of the Kuroshio Current was demonstrated. It is shown that their activity increases after the events of El-Niño and, hence, the thermal energy of the water area considerably increases and remains elevated for a period of 1–2 yr after the indicated events.Translated from Morskoi Gidrofizicheskii Zhurnal, No. 5, pp. 45–52, September–October, 2004.This revised version was published online in May 2005 with corrections to cover date.  相似文献   

Detection of DNA damage in mussels and sea urchins exposed to crude oil using comet assay     

Taban IC  Bechmann RK  Torgrimsen S  Baussant T  Sanni S 《Marine environmental research》2004,58(2-5):701-705

The single-cell microgel electrophoresis assay or the comet assay was used to evaluate DNA damage of dispersed crude oil on sea urchins (Strongylocentrotus droebachiensis) and mussels (Mytilus edulis L.). Sea urchins were exposed to 0.06 and 0.25 mg/L dispersed crude oil in a continuous flow system, while the mussels were exposed to 0.015, 0.06 and 0.25 mg/L dispersed crude oil. Sea urchin coelomocytes and mussel haemocytes were sampled after 4 and 5 weeks exposure, respectively. In the sea urchin coelomocytes, there was a significant concentration-related increase in the percentage of DNA in comet tail. In mussel haemocytes, there was a significantly higher percentage of DNA in comet tail for all treatments compared to the control. The responses were concentration-related up to 0.06 mg/L oil. The two highest exposure concentrations of mussels were not significantly different from each other. These results indicate that the comet assay can be used for biomonitoring of DNA damage in marine invertebrates following oil contamination.  相似文献   

Vertical distribution and feeding patterns in fish foraging on the krill Meganyctiphanes norvegica     

Onsrud  M.S.R.; Kaartvedt  S.; Rostad  A.; Klevjer  T.A. 《ICES Journal of Marine Science》2004,61(8):1278-1290

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